linux/tools/testing/selftests/bpf/progs/test_core_reloc_module.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright (c) 2020 Facebook */
   3
   4#include "vmlinux.h"
   5#include <bpf/bpf_helpers.h>
   6#include <bpf/bpf_core_read.h>
   7#include <bpf/bpf_tracing.h>
   8
   9char _license[] SEC("license") = "GPL";
  10
  11struct bpf_testmod_test_read_ctx {
  12        /* field order is mixed up */
  13        size_t len;
  14        char *buf;
  15        loff_t off;
  16} __attribute__((preserve_access_index));
  17
  18struct {
  19        char in[256];
  20        char out[256];
  21        bool skip;
  22        uint64_t my_pid_tgid;
  23} data = {};
  24
  25struct core_reloc_module_output {
  26        long long len;
  27        long long off;
  28        int read_ctx_sz;
  29        bool read_ctx_exists;
  30        bool buf_exists;
  31        bool len_exists;
  32        bool off_exists;
  33        /* we have test_progs[-flavor], so cut flavor part */
  34        char comm[sizeof("test_progs")];
  35        int comm_len;
  36};
  37
  38SEC("raw_tp/bpf_testmod_test_read")
  39int BPF_PROG(test_core_module_probed,
  40             struct task_struct *task,
  41             struct bpf_testmod_test_read_ctx *read_ctx)
  42{
  43#if __has_builtin(__builtin_preserve_enum_value)
  44        struct core_reloc_module_output *out = (void *)&data.out;
  45        __u64 pid_tgid = bpf_get_current_pid_tgid();
  46        __u32 real_tgid = (__u32)(pid_tgid >> 32);
  47        __u32 real_pid = (__u32)pid_tgid;
  48
  49        if (data.my_pid_tgid != pid_tgid)
  50                return 0;
  51
  52        if (BPF_CORE_READ(task, pid) != real_pid || BPF_CORE_READ(task, tgid) != real_tgid)
  53                return 0;
  54
  55        out->len = BPF_CORE_READ(read_ctx, len);
  56        out->off = BPF_CORE_READ(read_ctx, off);
  57
  58        out->read_ctx_sz = bpf_core_type_size(struct bpf_testmod_test_read_ctx);
  59        out->read_ctx_exists = bpf_core_type_exists(struct bpf_testmod_test_read_ctx);
  60        out->buf_exists = bpf_core_field_exists(read_ctx->buf);
  61        out->off_exists = bpf_core_field_exists(read_ctx->off);
  62        out->len_exists = bpf_core_field_exists(read_ctx->len);
  63
  64        out->comm_len = BPF_CORE_READ_STR_INTO(&out->comm, task, comm);
  65#else
  66        data.skip = true;
  67#endif
  68
  69        return 0;
  70}
  71
  72SEC("tp_btf/bpf_testmod_test_read")
  73int BPF_PROG(test_core_module_direct,
  74             struct task_struct *task,
  75             struct bpf_testmod_test_read_ctx *read_ctx)
  76{
  77#if __has_builtin(__builtin_preserve_enum_value)
  78        struct core_reloc_module_output *out = (void *)&data.out;
  79        __u64 pid_tgid = bpf_get_current_pid_tgid();
  80        __u32 real_tgid = (__u32)(pid_tgid >> 32);
  81        __u32 real_pid = (__u32)pid_tgid;
  82
  83        if (data.my_pid_tgid != pid_tgid)
  84                return 0;
  85
  86        if (task->pid != real_pid || task->tgid != real_tgid)
  87                return 0;
  88
  89        out->len = read_ctx->len;
  90        out->off = read_ctx->off;
  91
  92        out->read_ctx_sz = bpf_core_type_size(struct bpf_testmod_test_read_ctx);
  93        out->read_ctx_exists = bpf_core_type_exists(struct bpf_testmod_test_read_ctx);
  94        out->buf_exists = bpf_core_field_exists(read_ctx->buf);
  95        out->off_exists = bpf_core_field_exists(read_ctx->off);
  96        out->len_exists = bpf_core_field_exists(read_ctx->len);
  97
  98        out->comm_len = BPF_CORE_READ_STR_INTO(&out->comm, task, comm);
  99#else
 100        data.skip = true;
 101#endif
 102
 103        return 0;
 104}
 105
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